The brown tree snake can be distinguished by: vertical pupils, rear fangs, a large head in relation to the body, and a brownish or greenish coloring with cross-band markings. Coloration is constant at specific localities. The snake is about 18'' at hatching and may grow to about 3' in the first year. Adults can reach 8' and weight up to 5 lbs.
Detailed Description:
Reproduction:The female produces 4-12 oblong eggs, 42-47 mm long and 18-22 mm wide. They have a leathery shell and often adhere together after the shells dry. The female deposits the eggs in hollow logs, rock crevices, and other sites where they are likely protected from drying and high temperatures. Females may produce two clutches per year, but the timing may depend on seasonal variations in climate and prey abundance. Like other snake species, the female may be able to store sperm and produce eggs over several years after mating. Diet: These snakes eat frogs, lizards, small mammals, birds, and birds' eggs.Frogs and other snakes are eaten occasionally. Small snakes depend primarily on lizards, small birds, and eggs of lizards and birds, whereas larger individuals feed to a greater extent on adult birds, mammals, and larger prey items. Having nearly depleted the bird populations on Guam, larger snakes have been found scavenging garbage. Success:When threatened, the brown Treesnake is extremely aggressive and likely to lunge and bite repeatedly.
The snake has numerous teeth but only the last two on each side of the upper jaw have grooves, which inject venom as it bites. Thus, the mouth must be opened as wide as possible to insert these fangs, and a deliberate chewing movement is employed to inject the venom by means of capillary action along the grooved fangs. The venom is used to subdue and kill prey on which the snake normally feeds but is not considered dangerous to adult humans. The snake often wraps its body around the prey to immobilize it while chewing on the animal to inject the venom with its grooved teeth.
Habitat and Distribution:
The Brown treesnake occurs in grasslands and sparsely forested areas as well. In Papua New Guinea, it occupies a wide variety of habitats at elevations up to 1,200 m. It is most commonly found in trees, caves, and near limestone cliffs but frequently comes down to the ground to forage at night. It hides during the day in the crowns of palms, hollow logs, rock crevices, caves, and even the dark corners of thatched houses near the roof. Based on frequent mention of this snake in relation to buildings, domestic poultry, and caged birds, the snake is common in human-disturbed habitats and second-growth forests of primarily harmless snakes, and is native to coastal Australia, Papua New Guinea, and a large number of islands in northwestern Melanesia. The species occurs on both large and small islands, extending from Sulawesi in eastern Indonesia through Papua New Guinea and the Solomon Islands and into the wettest coastal areas of Northern Australia.
Impacts:
Positive Impacts: the brown tree snake's only benefits relate to the eradication of introduced species. For example, the voracious appetite of young snakes has helped to rid Guam of introduced lizards. Negative: The brown tree snake is responsible for an incredible decline in Guam's biodiversity. Over the past two decades, the brown tree snake has caused the disappearance of nearly all of the native forest birds on Guam, including the extinction of the Guam rail and the Micronesian kingfisher. Nine of the eleven avifauna species present at the time of the brown tree snake's introduction have since been extirpated. Of the species that have become extinct, five were endemic at the species or subspecies level.The abundance of the brown tree snake has also caused far-reaching secondary ecological impacts. The snake is responsible for the decline of the flying fox, a crucial species for the pollination and seed dispersal of tropical trees. Also, without the presence of certain avian insectivores, the insect population may experience a population boom and therefore negatively impact local agriculture. The cultural fabric of the island communities are negatively impacted by the brown tree snake as well. Fruit bats, an important part of indigenous rituals and celebrations on the Mariana Islands, have shown great declines since the introduction of the brown tree snake. The lower abundance of bats on the islands have not only limited this cultural practice but encouraged the exploitation of other areas in the Pacific for bat harvesting.In addition to these negative biological impacts, the brown tree snake threatens the economy of the island through large-scale electrical power outages and damages to equipment. Since 1978, over 1200 power outages have occurred as a result of the brown tree snake crawling onto high voltage electrical lines or entering transformers or residential appliances. Moreover, continuously increasing populations of the brown tree snake are responsible for predation of farm animals, poultry, and pets, leading to further economic consequences. These snakes are mildly venomous to humans and their non-fatal bite can cause severe sickness in young children
History:
The brown tree snake was accidentally introduced to Guam in the late 1940s or early 1950s, probably from the Solomon Islands. A native of Australia, Papua New Guinea, and the Solomon Islands, the brown tree snake is a dangerous threat to the economy and ecology of Guam and is the subject of a cooperative program to control snake populations on Guam and prevent its spread throughout the Pacific Rim.
Brown headed tree snake (Boiga Irregularis)
General Information:
The brown tree snake can be distinguished by: vertical pupils, rear fangs, a large head in relation to the body, and a brownish or greenish coloring with cross-band markings. Coloration is constant at specific localities. The snake is about 18'' at hatching and may grow to about 3' in the first year. Adults can reach 8' and weight up to 5 lbs.Detailed Description:
Reproduction: The female produces 4-12 oblong eggs, 42-47 mm long and 18-22 mm wide. They have a leathery shell and often adhere together after the shells dry. The female deposits the eggs in hollow logs, rock crevices, and other sites where they are likely protected from drying and high temperatures. Females may produce two clutches per year, but the timing may depend on seasonal variations in climate and prey abundance. Like other snake species, the female may be able to store sperm and produce eggs over several years after mating.
Diet: These snakes eat frogs, lizards, small mammals, birds, and birds' eggs.Frogs and other snakes are eaten occasionally. Small snakes depend primarily on lizards, small birds, and eggs of lizards and birds, whereas larger individuals feed to a greater extent on adult birds, mammals, and larger prey items. Having nearly depleted the bird populations on Guam, larger snakes have been found scavenging garbage.
Success: When threatened, the brown Treesnake is extremely aggressive and likely to lunge and bite repeatedly.
The snake has numerous teeth but only the last two on each side of the upper jaw have grooves, which inject venom as it bites. Thus, the mouth must be opened as wide as possible to insert these fangs, and a deliberate chewing movement is employed to inject the venom by means of capillary action along the grooved fangs. The venom is used to subdue and kill prey on which the snake normally feeds but is not considered dangerous to adult humans. The snake often wraps its body around the prey to immobilize it while chewing on the animal to inject the venom with its grooved teeth.
Habitat and Distribution:
The Brown treesnake occurs in grasslands and sparsely forested areas as well. In Papua New Guinea, it occupies a wide variety of habitats at elevations up to 1,200 m. It is most commonly found in trees, caves, and near limestone cliffs but frequently comes down to the ground to forage at night. It hides during the day in the crowns of palms, hollow logs, rock crevices, caves, and even the dark corners of thatched houses near the roof. Based on frequent mention of this snake in relation to buildings, domestic poultry, and caged birds, the snake is common in human-disturbed habitats and second-growth forests of primarily harmless snakes, and is native to coastal Australia, Papua New Guinea, and a large number of islands in northwestern Melanesia. The species occurs on both large and small islands, extending from Sulawesi in eastern Indonesia through Papua New Guinea and the Solomon Islands and into the wettest coastal areas of Northern Australia.Impacts:
Positive Impacts: the brown tree snake's only benefits relate to the eradication of introduced species. For example, the voracious appetite of young snakes has helped to rid Guam of introduced lizards.Negative: The brown tree snake is responsible for an incredible decline in Guam's biodiversity. Over the past two decades, the brown tree snake has caused the disappearance of nearly all of the native forest birds on Guam, including the extinction of the Guam rail and the Micronesian kingfisher. Nine of the eleven avifauna species present at the time of the brown tree snake's introduction have since been extirpated. Of the species that have become extinct, five were endemic at the species or subspecies level.
History:
The brown tree snake was accidentally introduced to Guam in the late 1940s or early 1950s, probably from the Solomon Islands. A native of Australia, Papua New Guinea, and the Solomon Islands, the brown tree snake is a dangerous threat to the economy and ecology of Guam and is the subject of a cooperative program to control snake populations on Guam and prevent its spread throughout the Pacific Rim.
Citations: